Mixing oil grades?
Author
Discussion

mattikake

Original Poster:

5,116 posts

228 months

Sunday 18th December 2011
quotequote all
Can it be done?

Seems Mobil 1 have discontinued fully synth Motorsport 15w50 and replaced it with a fully synth 10w60. frown

Given I have the 15w50 in my car currently and need an urgent top up, can I add some newer 10w60 with that ok or should I need a full oil change?

Remind me how it goes: Mixing heat ranges is ok but mixing semi-synth with fully-synth isn't?

powerstroke

10,283 posts

189 months

Monday 19th December 2011
quotequote all
mattikake said:
Can it be done?

Seems Mobil 1 have discontinued fully synth Motorsport 15w50 and replaced it with a fully synth 10w60. frown

Given I have the 15w50 in my car currently and need an urgent top up, can I add some newer 10w60 with that ok or should I need a full oil change?

Remind me how it goes: Mixing heat ranges is ok but mixing semi-synth with fully-synth isn't?
possibly ok with the slighty differnt grade however if it was me I would just change and keep a little extra for top ups , if is using a little oil use a cheaper make and change it sooner, my experience is clean cheap oil is better than dirty expensive stuff...

The Black Flash

13,735 posts

227 months

Monday 19th December 2011
quotequote all
mattikake said:
Can it be done?

Seems Mobil 1 have discontinued fully synth Motorsport 15w50 and replaced it with a fully synth 10w60. frown

Given I have the 15w50 in my car currently and need an urgent top up, can I add some newer 10w60 with that ok or should I need a full oil change?
Best do two, plus the filter, just to be on the safe side wink

JontyR

1,924 posts

196 months

Friday 23rd December 2011
quotequote all
Have a look at this chart, this is the one I use to blend the oils together to arrive at the specific weight of oil required.

Viscosity Chart

You will need to save the file

mrmr96

13,736 posts

233 months

Friday 23rd December 2011
quotequote all
mattikake said:
Can it be done?

Seems Mobil 1 have discontinued fully synth Motorsport 15w50 and replaced it with a fully synth 10w60. frown

Given I have the 15w50 in my car currently and need an urgent top up, can I add some newer 10w60 with that ok or should I need a full oil change?

Remind me how it goes: Mixing heat ranges is ok but mixing semi-synth with fully-synth isn't?
Per the recent thread on this topic. OIL BLENDS. So it will be totally fine to top it up with whatever you have to hand. The grade will just become a weighted average between what's been put in. Remember that having SOME oil is much more important than having the right grade.

TheEnd

15,370 posts

217 months

Friday 23rd December 2011
quotequote all
Yes, you can mix oils, Most manufacturers try to steer you to only topping up with their brand, but if they go into detail, you'll find the concern is usually because you'll then have something slightly different to what is in there, assuming that one is in there is correct.
ie. If you top up some fancy oil with something regular, you'll not have the same fancy qualities, but there isn't any problems with it congealing into tar or anything.

warch

2,941 posts

183 months

Friday 23rd December 2011
quotequote all
The Black Flash said:
Best do two, plus the filter, just to be on the safe side wink
rofl I just knew someone was going to say this...

Kitchski

6,551 posts

260 months

Saturday 24th December 2011
quotequote all
I'd eat my PC if you noticed a difference putting that in. I've run an engine on used LHM suspension fluid before! There are some engines which get prissy about oil grades (Ford Duratec springs to mind) but generally you'll be alright.
On the oil traing course I was sent on moons ago, mixing semi-syn with fully and mineral etc is ok, but mixing grades will affect oil performance.

JonathanC

628 posts

178 months

Sunday 25th December 2011
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Just posted this to the Audi, VW, Skoda section - but was also wondering if any of you guys can help me out, as I'm completely ignorant about oil grades.

The computer on my B8 A4 2.0T was indicating that I had only just above the minimum level of oil, so when I was in Costco the other day I bought a 4 litre can of fully synthetic Castrol EDGE 5W-40s.
I'm now concerned that the Audi dealer may have used a different grade of oil; does anyone here know which grade they're mostly likely to have used? I'm not going to be able to get hold of them on Christmas Day :-(
If they did use a different grade - and you know what it's likely to be - would you know whether the mix would be ok?

Edited by JonathanC on Sunday 25th December 04:43

JonathanC

628 posts

178 months

Sunday 25th December 2011
quotequote all
Just checked on the Castrol website, and they're recommending the Edge 5W-30 for my car - so I definitely filled up with the wrong one according to them.

Edited by JonathanC on Sunday 25th December 04:44

powerstroke

10,283 posts

189 months

Sunday 25th December 2011
quotequote all
JonathanC said:
Just checked on the Castrol website, and they're recommending the Edge 5W-30 for my car - so I definitely filled up with the wrong one according to them.

Edited by JonathanC on Sunday 25th December 04:44
I think most use 5/30 shell I very much doubt it will do any harm... its the tdi PD engines that are suposed to give trouble if the exact grade or type of oil isnt used...

mattikake

Original Poster:

5,116 posts

228 months

Sunday 25th December 2011
quotequote all
Thanks for the replies peeps. So it's a bit of a myth.

I topped up with 500ml of 10w60 fully synth and dawdled home at less than 3krpm. Seemed fine. Oil and filter change sometime over the next few days...

Merry christmas! smile

davepoth

29,395 posts

228 months

Sunday 25th December 2011
quotequote all
Remember - the difference between "max" and "min" on the dipstick is about 500ml, the sump usually holds around 5000ml, so if the weight of the oil is a different SAE code by ten, then it will average out as less than one different. And the oil in the engine gets thinner with age anyway. Chill.